Experimental study of a pre-cracked steel-concrete composite beam

A steel-concrete composite beam equipped with shear studs is loaded under a monotonic bending moment until failure. The originality and the interest of this experimental study lies in two different aspects: first, the concrete slab is transversally cracked before the beginning of the test because of restrained shrinkage strains; second, the experimental set-up includes the measures of slip at the steel-concrete interface and axial strain of some studs. The first and well-known result is that the behaviour of the beam may be divided into an elastic domain and a plastic domain with a significant ductility; the failure located in the central zone originates in high compressive strain in the concrete slab followed by crushing. Furthermore, the transverse cracks induce, mainly in the elastic domain, strong discontinuities in the longitudinal distribution of the slip and a noticeable evolution of the shear stud deflection scheme in the concrete slab. Numerical simulations performed within the elastic domain, accounting for slip or not, and at the ultimate stage according to Eurocodes are in good agreement with measurements for deflection and longitudinal strains.